The README_DEVELOPER document has become too long for many new contributors to quickly get going. The setup instructions were hidding far down inside the file and provided to many caveats for a quick setup. This splits out that information, streamlines it to take an opinionated stance on how to setup a development environment, and start the process of creating a set of documents tightly tied to the puppet codebase. This new docs area should be used for documents about developing on the puppet codebase, documentation of internal architecture, and other developer and development focussed documents. This also moves the acceptance test documents to this new location.